The goal of this project is to implement systematically different skin-directed and systemic modalities in healthy volunteers and patients to explore how human microbial communities are altered. In addition to identifying changes in host microbial communities, we have been working to develop ways to study the potential effects of microbiome alterations on host health and disease. In the last fiscal year, we have continued to recruit patients and healthy volunteers to participate and to provide biospecimens. Additionally, we are working with collaborators who have interventional protocols to investigate the composition of host microbial communities prior to and after implementation of systemic or topical interventions. These include studies of immunotherapy treatments in oncology patients and antimicrobials in human subjects.